---
id: rules
sidebar_label: Rules
title: Rules
description: Use Rasa Open Source rules to respond to FAQs, fill forms, or handle fallbacks gracefully.
abstract: Rules are a type of training data used to train your assistant's dialogue management model.
  Rules describe short pieces of conversations that should always follow the same path.
---

**Don't overuse rules**. Rules are great to handle small specific conversation patterns, but
unlike [stories](./stories.mdx), rules don't have the power to generalize to unseen conversation
paths. Combine rules and stories to make your assistant robust and able to handle
real user behavior.

If you can't decide whether to write a story or a rule to implement a certain behavior, see the
best practices for [Writing Conversation Data](./writing-stories.mdx)).

For additional examples on implementing rules in a Rasa assistant, refer to
our [Rules example bot](https://github.com/RasaHQ/rasa/tree/main/examples/rules).

## Writing a Rule

Before you start writing rules, you have to make sure that the
[Rule Policy](./policies.mdx#rule-policy) is added to your model configuration:

```yaml-rasa
policies:
- ... # Other policies
- name: RulePolicy
```

Rules can then be added to the `rules` section of your training data.

To indicate that a rule can apply at any point in a conversation, start with the
intent which starts the conversation and then add the actions which your assistant
should perform in response to that.

```yaml-rasa
rules:

- rule: Say `hello` whenever the user sends a message with intent `greet`
  steps:
  - intent: greet
  - action: utter_greet
```

This example rule applies at the start of conversation as well as when the user decides
to a send a message with an intent `greet` in the middle of an ongoing conversation.

Dialogue turns that only appear as rules in the training data and do not appear in stories
will be ignored by ML-only policies like `TEDPolicy` at prediction time.

```yaml-rasa
rules:
- rule: Say `hello` whenever the user sends a message with intent `greet`
  steps:
  - intent: greet
  - action: utter_greet

stories:
- story: story to find a restaurant
  steps:
  - intent: find_restaurant
  - action: restaurant_form
  - action: utter_restaurant_found
```

For example if you define the greeting rule as above and don't add it to any of your stories,
after `RulePolicy` predicts `utter_greet`, `TEDPolicy` will
make predictions as if the `greet, utter_greet` turn did not occur.


### Rules for the Conversation Start

To write a rule which only applies at the beginning of a conversation, add a
`conversation_start: true` to your rule:

```yaml-rasa
rules:

- rule: Say `hello` when the user starts a conversation with intent `greet`
  conversation_start: true
  steps:
  - intent: greet
  - action: utter_greet
```

If a user sends a message with the intent `greet` later in the conversation, the rule will not match.

### Rules with Conditions

Conditions describe requirements which have to be fulfilled for a rule to be
applicable. To do so, add any information about the prior conversation under the
`condition` key:

```yaml-rasa
rules:

- rule: Only say `hello` if the user provided a name
  condition:
  - slot_was_set:
    - user_provided_name: true
  steps:
  - intent: greet
  - action: utter_greet
```

Possible information that you can include under `condition` includes `slot_was_set` events
and `active_loop` events.

### Skip Waiting for User Input at the End of a Rule

By default, rules will wait for the next user message when finished with the last step:

```yaml-rasa
rules:

- rule: Rule which will wait for user message when it was applied
  steps:
  - intent: greet
  - action: utter_greet
  # - action: action_listen
  # Every rule implicitly includes a prediction for `action_listen` as last step.
  # This means that Rasa Open Source will wait for the next user message.
```

If you want to hand over the next action prediction to another story or rule, add
`wait_for_user_input: false` to your rule:

```yaml-rasa
rules:

- rule: Rule which will not wait for user message once it was applied
  steps:
  - intent: greet
  - action: utter_greet
  wait_for_user_input: false
```

This indicates that the assistant should execute another action
before waiting for more user input.

### Rules and Forms

When a [Form](./forms.mdx) is active, the bot will make predictions based on
how the form is defined, ignoring rules. Rules become applicable again if:

- the form fills all required slots
- the form rejects its execution (see
[Handling Unhappy Paths](./forms.mdx#writing-stories--rules-for-unhappy-form-paths) for
 more details)
